Many high-end cars have GPS navigation, phone dialing, Internet browsing and even text messaging capabilities built into the dashboard.

To address the problem, the agency is proposing new guidelines that would encourage automakers to design dash displays that disable while the vehicle is in motion.

"We recognize that vehicle manufacturers want to build vehicles that include the tools and conveniences expected by today's American drivers," NHTSA Administrator David Strickland said.

"The guidelines we're proposing would offer real world guidance to automakers to help them develop electronic devices that provide features consumers want without disrupting a driver's attention or sacrificing safety," he added.

Highway safety experts say the safest driver is one who has both hands on the wheel and the mind focused solely on driving.

Currently, there are no states that ban the use of hands-free devices for all drivers.